Cam actuated crimping pliers



Nov. 4,` 1952 H. P. DUPRE CAM ACTUATED CRIMPING PLIERS Filed Dec. 2,1948' iNVENTOR Ma/1w Bw if@ uw J5 ArroRN Patented Nov. 4, 1952 CAMACTUATED CRIMPING PLIERS Henry Peter Dupre, New York, N. Y., assignor toBurndy Engineering Company, Inc., a corporation of New York ApplicationDecember 2, 1948, Serial No. 63,068

2 Claims.

My invention relates to cam actuated tools, and particularly to such atool for crimping or indenting electrical connectors.

In the past, the only tool available for such purpose has been thestandard fulcrum type tool, employing single or multiple fulcrums.Sometimes these tools have been supplied with a link mechanism attachedto the handles permitting a variable mechanical advantage, The controlwas entirely dependent on the link` length, Which does not change thecharacteristic shape of the mechanical advantage curve.

I have adapted a cam actuated tool hitherto employed for other purposes,for indenting electrical connectors. I have discovered that the curve offorce needed for indentation purposes may be obtained from a suitablyshaped cam.

Accordingly the principal object of my invention consists in providing acompressing tool having a cam operated jaw, the cam being shaped so asto closely conform to the variable forces required to start, continueand complete the indentation of an electrical terminal to a conductor.

Other objects are to provide a hand operated compression tool whereinthe position of the tool handles, at the time when the maximum appliedpressures should be of the highest order, will permit the operatorslingers to span both handles enabling the maximum pressures to beapplied; to

provide a tool having a movable jaw which can be maintained in openposition by the same hand that supports the tool allowing the other handto be freed to position the connector; to provide such a tool having amovable jaw which will automatically grip the positioned work when thejaw is manually released; to provide means adapted to keep the jaws inopen position when the tool handles are opened; to provide spring.l

means which will close the jaws when the pressure holding the handlesapart is released; and to provide an arrangement of parts which willpermit maximum accessibility of the head of the tool in restrictedareas.

I accomplish these and other objects and obtain my new results as Willbe apparent from the device described in the following specification,particularly pointed out in the claims, and illustrated in theaccompanying drawing in which:

Fig. 1 is a partial front elevational view of the opened tool.

Fig. 2 is a longitudinally sectional view of the tool taken in the plane2 2 of Fig. 1.

Fig. 3 is a transversely sectioned view taken in the plane 3 3 in Figure2.

2 Fig. 4 is a side elevation view of the tool in final closed position,the handles being grasped by both hands of the operator. Referring moreparticularly to the drawing my tool shows in portable form a bodyvmember I- having a xed jaw I I at one end with an extending handle I2 atthe other, and a movable jaw I3 pivoted to the body at I4 and a movablelever I5 pivoted to the body at I6, having a cam I6a at one end foractuating the jaw.

The iixed and movable jaws I I and I3 are provided With complementaryworking members I'I and i3 respectively which are detachably affixed tothe jaws by screws I9 and 20.

A roller 2| is mounted to the movable jaw I3 which rides on the cam IEa,and fromione side of the jaw an opening member 22 extends, which may bea spring, and rides over a ridge 23 at the end of the cam when the leverI5 is opened. Thus the jaw is forced to open position against the actionof closing spring 24 one end of which is secured to the jaw by pin 25,the other being secured to the body by pin 26. Y

A finger hold 2I projects from the lever I5 to.

enable the thumb of the hand supporting the tool to hold the lever I5 inopen position against the action of closing spring 24, the jaw I3 thusbeing maintained in opened position through opening spring 22. The freehand may then be used to insert a connector 28 applied to a conductor 29to one of the grooves such as I1c of the working member, after which thethumb is freed from the finger hold 2 enabling the mov-A able jaw toclamp and hold the connector so that both hands may be used to operatethe tool.

The cam is designed to enable the maximum pressures to be applied whenneeded. This occurs when the indenting tooth I8c has collapsed theconnector wall and the conductor is being extruded into indentedposition. At that moment the lever I5 is positioned near the handle I2so that the lingers of both hands can be used to span both handles inwhich position the maximum pressures can be manually applied as shown inFigli.

The cam is provided with four surfaces running smoothly into each other.One is the curved section 30 which permitsy the roller to recede openingthe jaw to maximum width. Another surface 3I which causes the jaw to beclosed when the thumb frees the lever I5. A third is surface 32 whichcauses the handles to move to finger spanning position while theindentor Ic collapses the connector wall and starts the indentingoperation and lastly the 3 full indenting surface 33 where themechanical advantage is greatest and the spanned fingers can apply thegreatest force.

Three working positions are shown, namely grooves Ha, I'Ib and I 1c withcomplementary indentors 18a, I8b and I8c. The largest size connector ispositioned nearest the jaw pivot I4,

to permitA maximum pressures to be applied. It is apparent that any typeof working surfaces may be employed.

I am thus able by opening the tool fully to automatically open themovable jaw; holding it open by the same hand whichlsupports the tool.The jaws are then closed by'simp-ly releasing the nger hold; the leversclosing until the indentor clamps the connector. The lever is then usedto collapse the connector, the spanned ngers being next employed toapply the full indenting pressure.

I have thus describedl m-y invention, but I desire it understood that itis not conned to the particular forms or uses shown and described,the-,same being merely illustrative, and that the invention maybecarriedout in otherways withoutdeparting from the spirit of my invention and;therefore, I claim broadly the right to em- 1. A body member having ayfixed jaw' at one end amlv avsupportingstructure. for enabling the tool;to` be held in position; a lever having av hz'irldle-v portion pivotallymounted with. respect to. they body member; a. movable jaw' in opposing'relation to said xed jaw pivotally mounted with respect to the bodymember; said lever,` andimovable jaw being provided with av cam and a.follower for closing said movable jaw upon the' movement of said lever;spring biased meansV for urging the lever and movable jaw to closedposition, said lever having a finger hold portion at one end thereof forenabling the body member to be held with one hand with one linger in thehold to keep said lever open against the action of the spring biasedmeans.

2'. A body member having' a iixed jaw at one end, and a supporting"structure for enabling the tool to be held in position; a lever having ahandle portion pivotally mounted with respect to. thebody member; amovable jaw in opposing relation to said fixed jaw pivotally mountedwith respect. tol the body member; said lever and movable,` jaw' beingprovided with a cam and a follower for closing said movable jaw upon themovement of said lever; and a spring, one end of which is secure-d tothe movable jaw and the other end to the bodyrmember for urging themovable jaw into closed'position in all positions of the lever; saidmovable jaw provided with an extending arm -for engaging'y the lever4 inopenl position to open the movable jaw against. the action of thespring.

HENRY PETER DUPRE.

REFERENCES CITED- The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 174,142 Martin Feb. 29,v 1876732,850' Hayden July 7 1903 1,322,723 Norton et al. Nov. 25, 1919`1,353,847 Parker Sept. 28, 1920 1,358,241 Parker Nov. 9, 1920 1,435,131Jacobson Nov. '7, 1922 1,641,153 Butt Sept. 6. 1927 1,858,418 Rowley May17, 1932 2,288,348 Funk June 30, 1942 2,327,368 `Olson Aug. 24, 19432,382,292 Carlson Aug. 14, 1945* 2,404,028 Best July 16;.1946 v2,467,658 Carnelli Apr. 19, 1949 2,519,073 Schaub Aug.. 15*I 1950'

